The present disclosure generally relates to surgical instruments and their use. More particularly, the present disclosure relates to a collet locking and indexing system for surgical instruments.
Surgical instruments, in general, should satisfy several requirements in order to fulfill their various roles during surgery. One requirement is that certain components of a multi-part instrument, such as an instrument used for dissecting bone or tissue, should be aligned properly when the instrument is assembled. For example, alignment-sensitive components forming the instrument should be in certain positions relative to the other components when the instrument is originally assembled. Thereafter, each time the instrument is reassembled after being disassembled, each of the alignment-sensitive components should be returned to the same relative position. Among other benefits, consistent alignment ensures that the instrument is correctly positioned to receive a surgeon""s hand in an optimal manner. Such optimal alignment may take into account such factors as the location of any controls and the angle of a tool associated with the instrument, such as a cutting tool. If the alignment of the various components is not correct, a surgeon may be unable to access the controls when the cutting tool is properly positioned.
Typically, to ensure that the instrument is properly aligned, marks are placed on the exterior of the instrument in the following manner. The instrument, which often includes a locking device such as a collet, a motor and motor assembly, and an attachment, is fully assembled. The assembly process includes attaching the collet to the motor assembly, sliding the attachment over the collet, and securing the attachment to the collet. Marks may then be made on the exterior of the motor assembly and the attachment to indicate their relative positions (xe2x80x9clockedxe2x80x9d or xe2x80x9cunlockedxe2x80x9d) when the instrument is fully assembled. To attach a cutting tool, the attachment is loosened (moved to the xe2x80x9cunlockedxe2x80x9d position), the collet is opened and the tool is inserted into the collet. The collet is then closed to securely retain the tool and the attachment is tightened until the mark on the attachment is aligned with the corresponding mark on the motor assembly (the xe2x80x9clockedxe2x80x9d position). Accordingly, the alignment marks prevent the attachment from being over-tightened, which could damage the instrument, and from not being tightened enough, which could have disastrous consequences during surgery. As the alignment marks depend on the relative positions of the attachment, motor assembly, and collet, these components play an important role in the alignment process.
While frequently used, this post-assembly marking process presents a number of difficulties. For example, when one of the alignment-sensitive components in the instrument must be replaced, the instrument will likely need to be remarked. For example, if the collet must be replaced, the original collet must be removed and a new collet must be attached to the motor assembly. However, the likelihood that the new collet will accept the original attachment in exactly the same manner is doubtful. For example, if the motor assembly and the collet are threaded, there is very little likelihood that the threads of the new collet will engage the threads of the motor assembly in the exact manner as the old collet. Accordingly, the new collet will not be in the same position relative to the motor assembly as the old collet. Therefore, when the attachment is connected to the new collet, it is unlikely that the mark on the attachment will properly align with the mark on the motor assembly. As the markings are often permanent, one or more components that are otherwise perfectly functional may be discarded and replaced with unmarked components that can be marked appropriately.
Therefore, what is needed is a locking and indexing system that enables various alignment-sensitive components of a surgical instrument to be assembled in a consistent manner, allowing alignment markings to be placed on components before the instrument is assembled.
The present disclosure provides many technological advances that can be used, either alone or in combination, to provide an improved powered surgical instrument and/or an improved system and method for using powered surgical instruments.
In one embodiment, a locking system for a surgical instrument is provided. The locking system includes a collet having a first engagement element that corresponds with a second engagement element of a motor assembly. The first and second engagement elements prevent rotation of the collet relative to the motor assembly. The locking system also includes a slidable locking member operable to secure the collet to the motor housing.
In another embodiment, the first and second engagement elements are apertures operable to form a cavity around a rigid fastening member. In still another embodiment, one of the first and second engagement elements is a protuberance and the remaining first or second engagement element is an aperture operable to receive the protuberance.
In yet another embodiment, a surgical instrument is provided. The surgical instrument includes a collet including a first engaging means and a motor assembly operable to receive the collet in a cavity. The cavity includes a second engaging means operable to engage the first engaging means to prevent rotation of the collet relative to the motor housing. The surgical instrument also includes a locking element operable to secure the collet to the motor assembly.
In still another embodiment, a collet for insertion into a cavity of a surgical instrument is provided. The collet includes a distal portion having an opening for receiving a tool and a first fastening element for accepting an attachment. The collet also includes a proximal portion with a first alignment element for engaging a second alignment element present in the cavity. A locking member is included for securing the collet to the surgical instrument.
Further forms and embodiments of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.